Impact of unusually clear weather on United States daily temperature range following 9/11/2001

Adam J. Kalkstein*, Robert C. Balling Jr

ABSTRACT: Several investigators have suggested that the airline shutdown following the 9/11 terrorist attacks led to a reduction of jet contrails and an increase in the diurnal temperature range (DTR) across the US. Here, we use an air-mass approach to
control for weather conditions across the country following 9/11 in order to more accurately assess the observed patterns in the temperature range. We indeed find a higher-than-average DTR shortly after the attacks, but we find that the unusually clear
weather across the US more than accounts for the observed DTR.